The present invention relates to the field of battery charge and functionality testing. Developments in battery technology have increased battery storage capacities and overall battery performance. As a result, both non-rechargeable and rechargeable battery use has increased.
Batteries, and in particular rechargeable batteries, are used extensively in the medical and construction fields. This increased use of batteries has led to increased need for charge and battery maintenance. It is for example, particularly important for hospital personnel to quickly find sufficiently charged batteries in preparation for or during a surgical procedure.
As rechargeable batteries are not cheap, it is also important to maintain the batteries and to accurately verify when a battery needs to be replaced. With proper maintenance and monitoring, battery life and reliability can be increased.
Although battery testers are available on the market, there is a need for a tester which: can provided a quick indication of battery charge; reduce false indications; reduce the chance of inadvertent discharge; is compact, reliable, easy to use; and is inexpensive.
Often it is of great importance to determine charge level and functionality of a battery in a hurry. This is especially true in the medical profession where expediency is often critical.
Although several devices can provide quick checks of a battery's charge, they are inadequate in several respects. For example, a voltmeter or similar device can quickly measure a batteries voltage, however, it may allow a battery pack with a simple short cell to indicate a fully charged battery. Some testers utilize a resistive load heating element comprised of thermochromatic ink to give a visual read-out to the user. This method takes a period of time for a correct indication and may not adequately load a rechargeable battery. Some devices are integrated into the battery housing itself, possibly increasing leakage current and increasing battery cost. Additionally, such devices may not reliably withstand construction site elements or the high temperatures required for medical autoclave sterilization. Some devices even take five or more minutes to register battery charge level.
False indications are also a problem. Often debris or oxidation on the battery contacts or terminals can cause deteriorated performance and false battery charge indications. Rechargeable batteries in the medical field are particularly susceptible to oxidation or corrosion. This is due to the systematic exposure to autoclave heat and moisture that is required for sterilization.
False indications as to the actual voltage the battery can deliver when installed into the host device is also a problem. Batteries will often have a spring back voltage which is actually above the voltage the battery can actually deliver during use.
False indications can also occur in rechargeable batteries if there is a shorted cell. Such a failure could go undetected by typical charge indicators.
Inadvertent discharging of the testing device and the batteries is also a problem encountered by the prior art. If batteries are inadvertently left on the testing device, deletion of the internal energy source of the tester and also the draining of the rechargeable battery under test occurs.
Unlike the present invention, the prior art has not successfully addressed these many needs.